old capacitors - anybody use these?

[kgreene]

I have a few boxes of old capacitors that I am going to let go of, and just wondering if there is anyone who has any interest in them.

[Cliff Schecht]

Except for the green sangamo caps in the last picture, I wouldn't use any of those caps. How much for that box?

[Structo]

The ceramics are probably OK but the paper and wax caps are probably leaky.

The Sangamo's are probably good.

[jmohr58]

Comments from "Just Radios" a supplier of Caps and resistors for restoring old Radios: http://www.justradios.com/
This is a site out of Canada, and they may deal in old tube radios, but it is another source for High Voltage Caps as well as a variety of different types of resistors.
The following quotes are from their Capacitor Tips page:

Your old tube radio uses 4 types of capacitors: variable (tuning) capacitors, mica capacitors, paper capacitors and electrolytic (filter) capacitors. When you restore an antique radio you will replace the paper and electrolytic capacitors, but not the variable and mica capacitors.

I remember reading somewhere on their site that the Ceramic disks hold up just as well as Silver Mica caps do.

How about using NOS (New "Old Stock") capacitors? These are not recommended…use at own risk! As paper and electrolytic capacitors age their capacitance values drift, they dry out and they become leaky. Would you drive a 1930's automobile with NOS 70-year-old tires?

Old paper/wax capacitors are one of the most unreliable parts in an old radio. Don't let "molded" paper capacitors fool you. They are just paper capacitors in plastic cases and are just as unreliable as the ones coated in wax.

Electrolytic capacitors have a shelf life of a couple of years, so make sure you are buying "fresh" stock electrolytics (not new "old stock"). Would you buy stale loaf of bread if a fresh one available?

[M Fowler]

I would build cigar box guitars and throw most of the caps away!

[jmohr58]

Not sure about the caps, but the Cigar Boxes would be the Hidden Jewels in those pictures.

[jmohr58]

Delete - Accidental Duplicate Post

[rp]

You got Prince Albert in a can...?

[Ian444]

PM sent. Fair enough, not so good for new builds, but for restorations...
Thanks for the offer and thinking of us is all I can say!

[Alexo]

Wouldn't use the waxy caps in an amp, but they can be cool in guitar tone circuits.

[kgreene]

Thanks to all for the inquiries and comments. I made a swap with an early responder who contacted me, and they are all gone.

In response to some of your comments, I will tell you that I used to keep very old caps around from the 40's and 50's to use for restoration/repairs, all NOS. I would fish through and test caps when I found the right thing. Interestingly, some caps were obviously toast, others would drift once placed in circuit, and some were perfect and seemed almost indestructible - all within the same brand and type.
I wonder if others have had the same experience with old caps.

[Polich]

Hi guys,
Mick here -I'm a tube amp tech located in NW Iowa. I agreed on using those caps -the ceramic ones are probably o.k., but even the wax and paper caps can leak, so I would probably off those. Anyone who knows of tube amp owners in this area of the state that need repairs or service, feel free to send 'em my way - I've been working on gear since 1979.
Thanks,
Mick

[rp]

I wonder if others have had the same experience with old caps.

Yes. The drift can be outrageous, when buying old caps spend little and be prepared to throw 70% out, and that's overall, in a lifetime. I've gotten batches of 10-20 where 100% were 50%-200% off. Unlike other components being NOS is completely worthless here. Many people selling old caps on ebay are knowingly dumping junk. As for DC leakage, all the wax ones leak, the molded are a little better. If I go old I try and build with cheap new caps and get the amp up 100% and then afterwards swap in old caps one or two at a time and test and listen. Mind you, I build PTP so with me this is some sort of masochism disorder.

I don't think old caps have magic mojo, just that their shittyness can color a guitar amp really nicely. I'll have to try Sozos, maybe they have captured the shittyness.

[boots]

I don't know about the caps, but those cigar boxes are great! I have a friend who has been making some nice cigar box guitars.